Core Java for the Impatient

Preface
Acknowledgments
About the Author
1 FUNDAMENTAL PROGRAMMING STRUCTURES
1.1 Our First Program
1.1.1 Dissecting the “Hello, World” Program
1.1.2 Compiling and Running a Java Program
1.1.3 Method Calls
1.1.4 JShell
1.2 Primitive Types
1.2.1 Signed Integer Types
1.2.2 Floating-Point Types
1.2.3 The char Type
1.2.4 The boolean Type
1.3 Variables
1.3.1 Variable Declarations
1.3.2 Identifiers
1.3.3 Initialization
1.3.4 Constants
1.4 Arithmetic Operations
1.4.1 Assignment
1.4.2 Basic Arithmetic
1.4.3 Mathematical Methods
1.4.4 Number Type Conversions
1.4.5 Relational and Logical Operators
1.4.6 Big Numbers
1.5 Strings
1.5.1 Concatenation
1.5.2 Substrings
1.5.3 String Comparison
1.5.4 Converting Between Numbers and Strings
1.5.5 The String API
1.5.6 Code Points and Code Units
1.5.7 Text Blocks
1.6 Input and Output
1.6.1 Reading Input
1.6.2 Formatted Output
1.7 Control Flow
1.7.1 Branches
1.7.2 Switches
1.7.3 Loops
1.7.4 Breaking and Continuing
1.7.5 Local Variable Scope
1.8 Arrays and Array Lists
1.8.1 Working with Arrays
1.8.2 Array Construction
1.8.3 Array Lists
1.8.4 Wrapper Classes for Primitive Types
1.8.5 The Enhanced for Loop
1.8.6 Copying Arrays and Array Lists
1.8.7 Array Algorithms
1.8.8 Command-Line Arguments
1.8.9 Multidimensional Arrays
1.9 Functional Decomposition
1.9.1 Declaring and Calling Static Methods
1.9.2 Array Parameters and Return Values
1.9.3 Variable Arguments
Exercises
2 OBJECT-ORIENTED PROGRAMMING
2.1 Working with Objects
2.1.1 Accessor and Mutator Methods
2.1.2 Object References
2.2 Implementing Classes
2.2.1 Instance Variables
2.2.2 Method Headers
2.2.3 Method Bodies
2.2.4 Instance Method Invocations
2.2.5 The this Reference
2.2.6 Call by Value
2.3 Object Construction
2.3.1 Implementing Constructors
2.3.2 Overloading
2.3.3 Calling One Constructor from Another
2.3.4 Default Initialization
2.3.5 Instance Variable Initialization
2.3.6 Final Instance Variables
2.3.7 The Constructor with No Arguments
2.4 Records
2.4.1 The Record Concept
2.4.2 Constructors: Canonical, Custom, and Compact
2.5 Static Variables and Methods
2.5.1 Static Variables
2.5.2 Static Constants
2.5.3 Static Initialization Blocks
2.5.4 Static Methods
2.5.5 Factory Methods
2.6 Packages
2.6.1 Package Declarations
2.6.2 The jar Command
2.6.3 The Class Path
2.6.4 Package Access
2.6.5 Importing Classes
2.6.6 Static Imports
2.7 Nested Classes
2.7.1 Static Nested Classes
2.7.2 Inner Classes
2.7.3 Special Syntax Rules for Inner Classes
2.8 Documentation Comments
2.8.1 Comment Insertion
2.8.2 Class Comments
2.8.3 Method Comments
2.8.4 Variable Comments
2.8.5 General Comments
2.8.6 Links
2.8.7 Package, Module, and Overview Comments
2.8.8 Comment Extraction
Exercises
3 INTERFACES AND LAMBDA EXPRESSIONS
3.1 Interfaces
3.1.1 Using Interfaces
3.1.2 Declaring an Interface
3.1.3 Implementing an Interface
3.1.4 Converting to an Interface Type
3.1.5 Casts and the instanceof Operator
3.1.6 The “Pattern-Matching” Form of instanceof
3.1.7 Extending Interfaces
3.1.8 Implementing Multiple Interfaces
3.1.9 Constants
3.2 Static, Default, and Private Methods
3.2.1 Static Methods
3.2.2 Default Methods
3.2.3 Resolving Default Method Conflicts
3.2.4 Private Methods
3.3 Examples of Interfaces
3.3.1 The Comparable Interface
3.3.2 The Comparator Interface
3.3.3 The Runnable Interface
3.3.4 User Interface Callbacks
3.4 Lambda Expressions
3.4.1 The Syntax of Lambda Expressions
3.4.2 Functional Interfaces
3.5 Method and Constructor References
3.5.1 Method References
3.5.2 Constructor References
3.6 Processing Lambda Expressions
3.6.1 Implementing Deferred Execution
3.6.2 Choosing a Functional Interface
3.6.3 Implementing Your Own Functional Interfaces
3.7 Lambda Expressions and Variable Scope
3.7.1 Scope of a Lambda Expression
3.7.2 Accessing Variables from the Enclosing Scope
3.8 Higher-Order Functions
3.8.1 Methods that Return Functions
3.8.2 Methods That Modify Functions
3.8.3 Comparator Methods
3.9 Local and Anonymous Classes
3.9.1 Local Classes
3.9.2 Anonymous Classes
Exercises
4 INHERITANCE AND REFLECTION
4.1 Extending a Class
4.1.1 Super- and Subclasses
4.1.2 Defining and Inheriting Subclass Methods
4.1.3 Method Overriding
4.1.4 Subclass Construction
4.1.5 Superclass Assignments
4.1.6 Casts
4.1.7 Anonymous Subclasses
4.1.8 Method Expressions with super
4.2 Inheritance Hierarchies
4.2.1 Final Methods and Classes
4.2.2 Abstract Methods and Classes
4.2.3 Protected Access
4.2.4 Sealed Types
4.2.5 Inheritance and Default Methods
4.3 Object: The Cosmic Superclass
4.3.1 The toString Method
4.3.2 The equals Method
4.3.3 The hashCode Method
4.3.4 Cloning Objects
4.4 Enumerations
4.4.1 Methods of Enumerations
4.4.2 Constructors, Methods, and Fields
4.4.3 Bodies of Instances
4.4.4 Static Members
4.4.5 Switching on an Enumeration
4.5 Runtime Type Information and Resources
4.5.1 The Class Class
4.5.2 Loading Resources
4.5.3 Class Loaders
4.5.4 The Context Class Loader
4.5.5 Service Loaders
4.6 Reflection
4.6.1 Enumerating Class Members
4.6.2 Inspecting Objects
4.6.3 Invoking Methods
4.6.4 Constructing Objects
4.6.5 JavaBeans
4.6.6 Working with Arrays
4.6.7 Proxies
Exercises
5 EXCEPTIONS, ASSERTIONS, AND LOGGING
5.1 Exception Handling
5.1.1 Throwing Exceptions
5.1.2 The Exception Hierarchy
5.1.3 Declaring Checked Exceptions
5.1.4 Catching Exceptions
5.1.5 The Try-with-Resources Statement
5.1.6 The finally Clause
5.1.7 Rethrowing and Chaining Exceptions
5.1.8 Uncaught Exceptions and the Stack Trace
5.1.9 API Methods for Throwing Exceptions
5.2 Assertions
5.2.1 Using Assertions
5.2.2 Enabling and Disabling Assertions
5.3 Logging
5.3.1 Should You Use the Java Logging Framework?
5.3.2 Logging 101
5.3.3 The Platform Logging API
5.3.4 Logging Configuration
5.3.5 Log Handlers
5.3.6 Filters and Formatters
Exercises
6 GENERIC PROGRAMMING
6.1 Generic Classes
6.2 Generic Methods
6.3 Type Bounds
6.4 Type Variance and Wildcards
6.4.1 Subtype Wildcards
6.4.2 Supertype Wildcards
6.4.3 Wildcards with Type Variables
6.4.4 Unbounded Wildcards
6.4.5 Wildcard Capture
6.5 Generics in the Java Virtual Machine
6.5.1 Type Erasure
6.5.2 Cast Insertion
6.5.3 Bridge Methods
6.6 Restrictions on Generics
6.6.1 No Primitive Type Arguments
6.6.2 At Runtime, All Types Are Raw
6.6.3 You Cannot Instantiate Type Variables
6.6.4 You Cannot Construct Arrays of Parameterized Types
6.6.5 Class Type Variables Are Not Valid in Static Contexts
6.6.6 Methods May Not Clash after Erasure
6.6.7 Exceptions and Generics
6.7 Reflection and Generics
6.7.1 The Class Class
6.7.2 Generic Type Information in the Virtual Machine
Exercises
7 COLLECTIONS
7.1 An Overview of the Collections Framework
7.2 Iterators
7.3 Sets
7.4 Maps
7.5 Other Collections
7.5.1 Properties
7.5.2 Bit Sets
7.5.3 Enumeration Sets and Maps
7.5.4 Stacks, Queues, Deques, and Priority Queues
7.5.5 Weak Hash Maps
7.6 Views
7.6.1 Small Collections
7.6.2 Ranges
7.6.3 Unmodifiable Views
Exercises
8 STREAMS
8.1 From Iterating to Stream Operations
8.2 Stream Creation
8.3 The filter, map, and flatMap Methods
8.4 Extracting Substreams and Combining Streams
8.5 Other Stream Transformations
8.6 Simple Reductions
8.7 The Optional Type
8.7.1 Producing an Alternative
8.7.2 Consuming the Value If Present
8.7.3 Pipelining Optional Values
8.7.4 How Not to Work with Optional Values
8.7.5 Creating Optional Values
8.7.6 Composing Optional Value Functions with flatMap
8.7.7 Turning an Optional into a Stream
8.8 Collecting Results
8.9 Collecting into Maps
8.10 Grouping and Partitioning
8.11 Downstream Collectors
8.12 Reduction Operations
8.13 Primitive Type Streams
8.14 Parallel Streams
Exercises
9 PROCESSING INPUT AND OUTPUT
9.1 Input/Output Streams, Readers, and Writers
9.1.1 Obtaining Streams
9.1.2 Reading Bytes
9.1.3 Writing Bytes
9.1.4 Character Encodings
9.1.5 Text Input
9.1.6 Text Output
9.1.7 Reading and Writing Binary Data
9.1.8 Random-Access Files
9.1.9 Memory-Mapped Files
9.1.10 File Locking
9.2 Paths, Files, and Directories
9.2.1 Paths
9.2.2 Creating Files and Directories
9.2.3 Copying, Moving, and Deleting Files
9.2.4 Visiting Directory Entries
9.2.5 ZIP File Systems
9.3 HTTP Connections
9.3.1 The URLConnection and HttpURLConnection Classes
9.3.2 The HTTP Client API
9.4 Regular Expressions
9.4.1 The Regular Expression Syntax
9.4.2 Testing a Match
9.4.3 Finding All Matches
9.4.4 Groups
9.4.5 Splitting along Delimiters
9.4.6 Replacing Matches
9.4.7 Flags
9.5 Serialization
9.5.1 The Serializable Interface
9.5.2 Transient Instance Variables
9.5.3 The readObject and writeObject Methods
9.5.4 The readExternal and writeExternal Methods
9.5.5 The readResolve and writeReplace Methods
9.5.6 Versioning
9.5.7 Deserialization and Security
Exercises
10 CONCURRENT PROGRAMMING
10.1 Concurrent Tasks
10.1.1 Running Tasks
10.1.2 Futures
10.2 Asynchronous Computations
10.2.1 Completable Futures
10.2.2 Composing Completable Futures
10.2.3 Long-Running Tasks in User-Interface Callbacks
10.3 Thread Safety
10.3.1 Visibility
10.3.2 Race Conditions
10.3.3 Strategies for Safe Concurrency
10.3.4 Immutable Classes
10.4 Parallel Algorithms
10.4.1 Parallel Streams
10.4.2 Parallel Array Operations
10.5 Threadsafe Data Structures
10.5.1 Concurrent Hash Maps
10.5.2 Blocking Queues
10.5.3 Other Threadsafe Data Structures
10.6 Atomic Counters and Accumulators
10.7 Locks and Conditions
10.7.1 Locks
10.7.2 The synchronized Keyword
10.7.3 Waiting on Conditions
10.8 Threads
10.8.1 Starting a Thread
10.8.2 Thread Interruption
10.8.3 Thread-Local Variables
10.8.4 Miscellaneous Thread Properties
10.9 Processes
10.9.1 Building a Process
10.9.2 Running a Process
10.9.3 Process Handles
Exercises
11 ANNOTATIONS
11.1 Using Annotations
11.1.1 Annotation Elements
11.1.2 Multiple and Repeated Annotations
11.1.3 Annotating Declarations
11.1.4 Annotating Type Uses
11.1.5 Making Receivers Explicit
11.2 Defining Annotations
11.3 Standard Annotations
11.3.1 Annotations for Compilation
11.3.2 Meta-Annotations
11.4 Processing Annotations at Runtime
11.5 Source-Level Annotation Processing
11.5.1 Annotation Processors
11.5.2 The Language Model API
11.5.3 Using Annotations to Generate Source Code
Exercises
12 THE DATE AND TIME API
12.1 The Time Line
12.2 Local Dates
12.3 Date Adjusters
12.4 Local Time
12.5 Zoned Time
12.6 Formatting and Parsing
12.7 Interoperating with Legacy Code
Exercises
13 INTERNATIONALIZATION
13.1 Locales
13.1.1 Specifying a Locale
13.1.2 The Default Locale
13.1.3 Display Names
13.2 Number Formats
13.3 Currencies
13.4 Date and Time Formatting
13.5 Collation and Normalization
13.6 Message Formatting
13.7 Resource Bundles
13.7.1 Organizing Resource Bundles
13.7.2 Bundle Classes
13.8 Character Encodings
13.9 Preferences
Exercises
14 COMPILING AND SCRIPTING
14.1 The Compiler API
14.1.1 Invoking the Compiler
14.1.2 Launching a Compilation Task
14.1.3 Capturing Diagnostics
14.1.4 Reading Source Files from Memory
14.1.5 Writing Byte Codes to Memory
14.2 The Scripting API
14.2.1 Getting a Scripting Engine
14.2.2 Evaluating Scripts
14.2.3 Bindings
14.2.4 Redirecting Input and Output
14.2.5 Calling Scripting Functions and Methods
14.2.6 Compiling a Script
Exercises
15 THE JAVA PLATFORM MODULE SYSTEM
15.1 The Module Concept
15.2 Naming Modules
15.3 The Modular “Hello, World!” Program
15.4 Requiring Modules
15.5 Exporting Packages
15.6 Modules and Reflective Access
15.7 Modular JARs
15.8 Automatic Modules
15.9 The Unnamed Module
15.10 Command-Line Flags for Migration
15.11 Transitive and Static Requirements
15.12 Qualified Exporting and Opening
15.13 Service Loading
15.14 Tools for Working with Modules
Exercises
Index